The use of circular surgical staplers for end-to-end, end-to-side, and side-to-side anastomoses, and for others uses in vivo, is well known. A particular example of such a stapler includes the stapler described in U.S. Pat. No. 5,104,025, entitled “Intraluminal Anastomotic Surgical Stapler with Detached Anvil,” wherein an anvil assembly is mounted on the end of a pointed center rod to be manipulated relative to a staple assembly on the end of a tubular housing of the instrument, in order to drive staples through the desired tissue, against the anvil backing, to create the desired connection. The pointed center rod is retractable into the head of the surgical stapler, such that it may be hidden during insertion of the stapler head to the target tissue site. Recently, surgical staplers have been employed in laparoscopic operations by passing the stapler through a small incision in the abdominal wall. However, the head is shaped such that it is difficult to unintrusively advance the head through the abdominal tissue to the target tissue site, and the prior art has provided tapered introducers to fit onto the center rod to provide the head with a tapered insertion end to aid in such introduction.
The present invention addresses what is seen to be failures of the prior art in such tapered introducer designs, and an improved introducer is provided.